Robustifying imageBrowser w/ respect to missing dates for some visits

slicerModules/imageBrowser.py

@@ -311,8 +311,8 @@ class imageBrowserWidget(ScriptedLoadableModuleWidget):
         try:
             seq={row['SequenceNum']:
                 {'label':row[visitVar],
-                'date': parseDate(row['studyDate'])}
-                for row in ds['rows']}
+                'date': parseDate(row.get('studyDate'))}
+                for row in ds['rows'] if row.get('studyDate')}
         except TypeError:
             #if studyDate is empty, this will return no possible visits
             print('[{}]: failed to parse studyDates'.format(self.patientList.currentText))
@@ -949,6 +949,8 @@ class imageBrowserTest(ScriptedLoadableModuleTest):
 
 #utility funcitons
 def parseDate(x):
+   if not x:
+      return x
    dt=datetime.datetime
    formats=['%Y/%m/%d %H:%M:%S','%Y-%m-%d %H:%M:%S.%f']
    #print(f'Converting {x}')